U.S. patent application number 13/990894 was filed with the patent office on 2013-11-14 for fitting for a vehicle seat.
This patent application is currently assigned to KEIPER GMBH & CO. KG. The applicant listed for this patent is Christoph Peters. Invention is credited to Christoph Peters.
Application Number | 20130300175 13/990894 |
Document ID | / |
Family ID | 45047718 |
Filed Date | 2013-11-14 |
United States Patent
Application |
20130300175 |
Kind Code |
A1 |
Peters; Christoph |
November 14, 2013 |
FITTING FOR A VEHICLE SEAT
Abstract
A fitting for a vehicle seat includes a first fitting part and a
second fitting part, which can be rotated relative to each other,
bolts which, in the locked state, interact with a toothed ring on
the first fitting part to lock the fitting, and a rotatably mounted
eccentric, which acts on the bolts when changing from the unlocked
state to the locked state by rotation in a closing direction. When
in the locked state without any external torque, a first eccentric
cam and a first locking cam are in contact with each other at a
first contact point and there is a gap between the second eccentric
cam and a second locking cam. Starting at a specific external
torque, the second eccentric cam and the second locking cam are in
contact with each other at a second contact point.
Inventors: |
Peters; Christoph;
(Wermelskirchen, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Peters; Christoph |
Wermelskirchen |
|
DE |
|
|
Assignee: |
KEIPER GMBH & CO. KG
|
Family ID: |
45047718 |
Appl. No.: |
13/990894 |
Filed: |
November 25, 2011 |
PCT Filed: |
November 25, 2011 |
PCT NO: |
PCT/EP2011/005930 |
371 Date: |
July 26, 2013 |
Current U.S.
Class: |
297/367P |
Current CPC
Class: |
B60N 2/433 20130101;
B60N 2205/20 20130101; B60N 2/2356 20130101; B60N 2/236
20150401 |
Class at
Publication: |
297/367.P |
International
Class: |
B60N 2/235 20060101
B60N002/235; B60N 2/433 20060101 B60N002/433 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 1, 2010 |
DE |
10 2010 053 525.7 |
Claims
1. A fitting for a vehicle seat having a backrest, the fitting
comprising: a first fitting member and a second fitting member,
which can be pivoted relative to each other about an axis, a
toothed ring being constructed on the first fitting member and
guiding segments being constructed on the second fitting member; at
least one bar which can be radially displaced by the guiding
segments in a guided manner between a locked state and an unlocked
state and which in the locked state co-operates with the toothed
ring in order to lock the fitting, the at least one bar having a
first locking cam and a second locking cam and no additional
locking cams; and a rotatably supported eccentric which, during
movement from the unlocked state to the locked state by rotation in
a closure direction, acts on the bar, the eccentric having for the
bar precisely one first eccentric cam which is suitable for
co-operation with the first locking cam and precisely one second
eccentric cam which is suitable for co-operation with the second
locking cam, the first eccentric cam and the first locking cam
being in contact with each other at a first contact location in the
locked state without any external torque on the backrest, wherein
in the locked state without any external torque on the backrest
there is a gap between the second eccentric cam and the second
locking cam, in the locked state, from a specific external torque
on the backrest, the second eccentric cam and the second locking
cam are in contact with each other at a second contact location, at
the first contact location between the first eccentric cam and the
first locking cam a first wedge angle which is positive is defined,
and at the second contact location between the second eccentric cam
and the second locking cam a second wedge angle which is negative
is defined.
2. The fitting as claimed in claim 1, wherein the first eccentric
cam follows in the closure direction and the second eccentric cam
leads in the closure direction.
3. The fitting as claimed in claim 1, wherein the first eccentric
cam leads in the closure direction and the second eccentric cam
follows in the closure direction.
4. The fitting as claimed in claim 1, wherein a plurality of bars
are provided.
5. The fitting as claimed in claim 4, wherein the eccentric
co-operates with four bars and the eccentric for co-operation with
each of the bars has precisely one first eccentric cam which is
suitable for co-operation with the first locking cam, respectively,
and precisely one second eccentric cam which is suitable for
co-operation with the second locking cam, respectively.
6. The fitting as claimed in claim 4, wherein, of two adjacent
bars, one of the two bars has a leading first eccentric cam in the
closure direction and the other of the two bars has a following
first eccentric cam in the closure direction.
7. The fitting as claimed in claim 4, wherein, of two radially
opposing bars, one of the two bars has a leading first eccentric
cam the closure direction and the other of the two bars has a
following first eccentric cam in the closure direction.
8. The fitting as claimed in claim 1, wherein at least one of the
bars can tilt within a bar guide which comprises two guiding
segments.
9. The fitting as claimed in claim 8, wherein the bars tilt in
opposing directions with respect to the closure direction.
10. The fitting as claimed in claim 1, wherein the first wedge
angle and/or the second wedge angle has/have a value smaller than
5.7.degree..
11. The fitting as claimed in claim 1, wherein the first wedge
angle and the second wedge angle at the associated contact
locations are defined as angles between the resultant force through
the axis and the normal force in the closure direction.
12. The fitting as claimed in claim 1, wherein the eccentric cams
and/or the locking cams are constructed in a convex manner.
13. The fitting as claimed in claim 1, wherein a control cam which
is connected to the eccentric in a rotationally secure manner and
which co-operates with projections of the bars in order during
unlocking to bring the toothed ring and the bars out of engagement
counter to the resilient loading of the eccentric.
14. The fitting as claimed in claim 1, wherein a gripping ring
axially holds together the first ting member and the second fitting
member.
15. A vehicle seat having at least one fitting as claimed in claim
1.
Description
[0001] The invention relates to a fitting for a vehicle seat having
the features of the preamble of claim 1.
[0002] A fitting of this type is known from EP1195115 B1. In the
locked state, the eccentric acts on the two locking cams of the two
bars with both eccentric cams. The wedge angle at the cam pair
following in the closure direction is negative.
[0003] EP1806072 B1 describes a fitting whose eccentric has three
eccentric cams, and the two bars accordingly have three locking
cams. The cams of the central cam pair are in contact with each
other in the locked state and have a negative wedge angle. In the
leading cam pair there is a gap, which is also the case with the
following cam pair. In the case of an external torque, a gap
disappears. The pair of cams which come into contact with each
other may co-operate in two different manners since the eccentric
cam has two different wedge angles, whilst the locking cam has two
convex regions which are separated from each other by means of a
concave intermediate region.
[0004] In order to increase the strength of a fitting, with at the
same time tolerance compensation of the play between the bar and
bar guide, it is proposed in DE 10 2005 046 806 B3 that each bar
with the fitting locked can be tilted within the bar guides in the
opposite direction to the bars which are adjacent in each case.
[0005] With a fitting disclosed in DE 10 2005 046 807 B3, the
spring arrangement which acts on the eccentric has two springs
which are fitted one inside the other and which act counter to
opening of the fitting. However, such a spring arrangement is
complex to assemble and adds considerable additional weight in
comparison with a spring arrangement having only one spring.
[0006] An object of the invention is to improve a fitting of the
type mentioned in the introduction. This object is achieved as
claimed in the invention with a fitting having the features of
claim 1. Advantageous embodiments are set out in the dependent
claims.
[0007] The positive wedge angle at the first cam pair serves to
lock the bar and to compensate for tolerance. The normal force with
an opening component is compensated for in a self-locking manner by
the friction forces. The negative wedge angle at the second cam
pair serves to lock the rotation of the eccentric under load. The
normal force has a closing component. In the locked state, the
first eccentric cam abuts the first locking cam. Without any
external torque on the backrest, however, there is a gap between
the second eccentric cam and the second locking cam. Only from a
specific external torque on the backrest do the second eccentric
cam and the second locking cam come into contact with each other at
a second contact location. Depending on the load direction on the
backrest, it is advantageous for the first eccentric cam to be
either leading or following in the closure direction of the
eccentric.
[0008] The invention is not limited to a specific number of bars.
Preferably, the number of bars is two, three or four bars. In
fittings having a plurality of bars, the strength of the fitting
can be further optimized by one of the two bars from two adjacent
bars having a first eccentric cam which leads in the closure
direction and the other of the two bars having a first eccentric
cam which follows in the closure direction. The load increasing
effect described can thus be used in an optimal manner for both
load directions acting on the backrest (in and counter to the
travel direction). In fittings with an even number of bars, two
radially opposing bars may also be constructed in such a manner
that one of the two opposing bars has a first eccentric cam which
leads in the closure direction and the other of the two bars has a
first eccentric cam which follows in the closure direction.
[0009] The invention is explained in greater detail below with
reference to an embodiment illustrated in the drawing, in
which:
[0010] FIG. 1 is a partial view in the region between the eccentric
and a bar,
[0011] FIG. 2 is an axial section through the embodiment,
[0012] FIG. 3 is a radial section through the embodiment along the
line in FIG. 2, and
[0013] FIG. 4 is a schematic illustration of a vehicle seat.
[0014] A vehicle seat 1 for a motor vehicle has a seat member 3 and
a backrest 4 which can be adjusted in terms of its inclination
relative to the seat member 3. In order to adjust the inclination
of the backrest 4, there is manually rotated, for example by means
of a hand-operated lever 5, a transmission rod 7 which is arranged
horizontally in the transition region between the seat member 3 and
backrest 4. At both sides of the vehicle seat 1, the transmission
rod 7 engages in a fitting 10. The transmission rod 7 defines the
used directional indications of a cylindrical co-ordinate
system.
[0015] The fitting 10 has a first fitting member 11 and a second
fitting member 12 which can be rotated relative to each other about
an axis A. The (notional) axis A is in alignment in this instance
with the transmission rod 7. The two fitting members 11 and 12 can
each be inscribed approximately in a circular disk form. Both
fitting members 11 and 12 preferably comprise metal, in particular
steel, which can be at least partially hardened. In order to
receive the axially acting forces, that is to say, in order to
axially hold together the fitting members 11 and 12, a gripping
ring 13 is provided. The gripping ring 13 preferably comprises
metal, in particular steel, which is preferably non-hardened. The
gripping ring 13 preferably has a substantially planar annular form
but may in an alternative embodiment be profiled in an L-shaped
manner having a cylindrical portion and, at the end face, a planar
annular portion.
[0016] The gripping ring 13 is securely connected to one of the two
fitting members 11 and 12, in this case in an external annular
portion to the second fitting member 12, for example by means of
laser welding or by means of another fixing technique known per se.
By means of an internal annular portion which is arranged in a
plane perpendicular relative to the axial direction, the gripping
ring 13, optionally with a sliding ring being interposed, engages
over the first fitting member 11 in the radially external edge
region thereof, without impeding the relative movement of the two
fitting members 11 and 12. In addition, the mutually facing inner
faces of the two fitting members 11 and 12 are protected from the
introduction of foreign bodies and contamination and damage.
[0017] The gripping ring 13 and the fitting member 11 or 12 which
is securely connected thereto therefore grip the other of the two
fitting members 11 and 12 that can be moved relative thereto. From
a structural viewpoint, the two fitting members 11 and 12 therefore
together form (with the gripping ring 13) a disk-like unit.
[0018] With the assembly of the fitting 10, the first fitting
member 11 is, for example, securely connected to the structure of
the backrest 4, that is to say, secured to the backrest. The second
fitting member 12 is then securely connected to the structure of
the seat member 3, that is to say, secured to the seat member.
However, the associations of the fitting members 11 and 12 may also
be transposed, that is to say, the first fitting member 11 would
then be secured to the seat member and the second fitting member 12
would be secured to the backrest. The fitting 10 is located in the
force path between the backrest 4 and seat member 3.
[0019] The fitting 10 is constructed as a catch fitting in which
the first fitting member 11 and the second fitting member 12 can be
locked together, as described, for example, in DE 10 2006 015 560
B3 whose disclosure is expressly incorporated herein by
reference.
[0020] The second fitting member 12 has--in this instance
four--guiding segments 14 which guide in pairs a bar 16 laterally
in a radial direction with straight guiding faces. The bars 16--in
this instance a total of four bars 16--are arranged in a state
offset--in this instance through 90.degree.--relative to each other
in a structural space defined between the two fitting members 11
and 12. The bars 16 are provided at the radially outer end thereof
with a tooth arrangement, which may move (fall) into engagement
with a toothed ring 17 of the first fitting member 11 which is
constructed as an internally toothed wheel. When the toothed ring
17 and the bars 16 co-operate, the fitting 10 is locked. In an
alternative configuration, the number of bars is one, two, three or
more than four bars.
[0021] The first fitting member 11 is arranged in a recess of the
second fitting member 12 and is overlapped thereby in a radially
outward direction, whereby the two fitting members 11 and 12
support each other. In this instance, the radially outer edge
region of the first fitting member 11 is arranged with the toothed
ring 17 in a radial direction between the guiding segments 14 and
the radially outer edge region (which serves to support the first
fitting member 11) of the second fitting member 12. With high
loads, for example in the event of a crash, the first fitting
member 11--after deformation--may move with its toothed ring 17
into abutment with the guiding segments 14 which are closer in the
load direction and which have correspondingly (concentrically)
curved faces in the direction towards the toothed ring 17. This
increases the strength of the fitting 10.
[0022] The first fitting member 11 may be supported in the second
fitting member 12. However, the relationships could be precisely
transposed, that is to say, the second fitting member 12 may be
supported on the first fitting member 11. In principle, however,
both arrangements are equally advantageous.
[0023] There is arranged at the center of the fitting 10 a carrier
21 which comprises, for example, plastics material and which is
rotatably supported on at least one of the two fitting members 11
and 12, in this instance the first fitting member 11, more
precisely in a central opening thereof. At both vehicle seat sides,
the carrier 21 is connected in a rotationally secure manner or at
least coupled for joint movement with the transmission rod 7 which
is introduced into a hole 23 of the hollow carrier 21 and on which
the hand-operated lever 5 rests in a rotationally secure manner. At
one end of the carrier 21, in the present case the one on the
second fitting member 12, there is provided a securing ring 24
which comprises plastics material in this instance and which is
preferably secured to the carrier 21 by means of ultrasound
welding. The hand-operated lever 5 may be securely clipped to the
securing ring 24 in a rotationally secure manner. The securing ring
24 may also be provided at the other end of the carrier 21 or be
provided at both ends, respectively.
[0024] There rests on the carrier 21 in a rotationally secure
manner or at least in a manner coupled for joint movement an
eccentric 27, which is arranged in the structural space defined
between the fitting members 11 and 12. The eccentric 27 has along
the outer periphery thereof for each bar 16, that is to say, in
this case, four-fold, a first eccentric cam 27a which is provided
for co-operation with a first locking cam 16a and--offset in a
peripheral direction relative thereto--a second eccentric cam 27b
which is provided for co-operation with a second locking cam 16b.
The eccentric cams 27a and 27b are directed radially outwards and
the locking cams 16a and 16b are directed radially inwards from the
respective bar 16.
[0025] A spring arrangement 35, for example one or two helical
springs which are fitted one inside the other, is arranged in a
central receiving member of one of the two fitting members 11 and
12, in this instance of the second fitting member 12, and in this
instance supported at the outer side. The spring arrangement 35
acts on the eccentric 27, in this instance by being supported at
the inner side on the carrier 21 in a rotationally secure manner.
Such a spring arrangement 35 is described, for example, in DE 10
2005 046 807 B3, whose disclosure is expressly incorporated herein
by reference. The eccentric 27 acted on by the spring arrangement
35 acts on the radially movable bars 16 and acts thereon in such a
manner that they are pressed radially outwards in order to fall
into the toothed ring 17, whereby the fitting 10 is locked.
[0026] A control cam 36 is arranged in the structural space axially
between the bars 16 and the first fitting member 11 and rests in
this instance on the eccentric 27 in a rotationally secure manner.
The control cam 36 has--in this instance four--control paths which
each co-operate with a projection 38 of each bar 16. The
projections 38 protrude in an axial direction from the bars 16
which are associated therewith. During rotation (by a few degrees)
of the carrier 21--and the eccentric 27, which is driven thereby,
and the control cam 36--counter to the force of the spring
arrangement 35, the control cam 36 pulls the bars 16 radially
inwards, that is to say, out of the toothed ring 17, whereby the
fitting 10 is unlocked and the two fitting members 11 and 12 can be
pivoted relative to each other about the axis A. The backrest 4 can
now be pivoted about the axis A in order to adjust the inclination
thereof, that is to say, in order to assume another position for
use.
[0027] The closure direction of the eccentric 27 is the rotation
direction of the eccentric 27 which acts in a closing manner owing
to the action by the spring arrangement 35. The co-operation of the
eccentric 27 with one of the bars 16 is considered below, the
closure direction being in the clockwise direction in FIG. 1, and
the first eccentric cam 27a following in the closure direction and
the second eccentric cam 27b leading in the closure direction.
[0028] In the locked state without loading of the backrest 4 (that
is to say, without any external torque and only with the torque
brought about by the weight of the backrest 4), the eccentric 27
acts only by means of the first eccentric cam 27a thereof on the
associated first locking cams 16a, to be precise at a first contact
location P1 (at which the first eccentric cam 27a and the first
locking cam 16a are in contact with each other), whilst, between
the second eccentric cam 27b and the associated second locking cam
16b, there is a gap of from approximately 0.05 to 0.5 mm,
preferably approximately 0.25 mm. The resultant forces K1 at the
first four contact locations P1 in each case extend through the
center point of the fitting 10, that is to say, through the axis A,
so that they generally neutralize each other. In the first contact
location P1, the first eccentric cam 27a and the associated first
locking cam 16a touch each other, that is to say, with the same
pitch and a common tangent. The normal force N1 at the first
contact location P1, which is directed radially inwards
perpendicularly relative to this tangent, is at an angle relative
to the resultant force K1 which is referred to as a first wedge
angle .alpha. and which at the same time corresponds to the angle
between the tangent at the first contact location P1 and the
circular arc about the axis A through the first contact location
P1.
[0029] The closure direction c determines how the first wedge angle
.alpha. is measured. The first wedge angle .alpha. is positive,
that is to say, when viewed in the figures, the following regions
of the first eccentric cam 27a in the closure direction c protrude
radially further outwards than the leading regions so that the bar
16 which is acted on by the first eccentric cam 27a is locked and
tolerance compensation is possible. The normal force N1 at the
first contact location P1 acts in an opening manner, but is
compensated for in a self-locking manner by the friction so that
said resultant force K1 is produced. As claimed in the invention,
the first wedge angle .alpha. is smaller than 5.7.degree.,
preferably smaller than 4.5.degree.. The first eccentric cam 27a
and the first locking cam 16a are material portions which are
constructed in a convex manner, at least generally in the region in
which the first contact location P1 may be located.
[0030] If, in the locked state, a load acts on the backrest 4, this
torque attempts to rotate the toothed ring 17 relative to the
guiding segments 14. The bars 16 are guided with play between the
guiding segments 14 and are on the one hand in engagement with the
toothed ring 17 and on the other hand supported on the associated
first eccentric cam 27a. The torque on the backrest 4 therefore
tilts the bars 16. When the torque in the drawing acts in a
counter-clockwise direction, the bar 16 tilts to the left (and
contacts the left-hand guiding segment 14) and the resultant force
at the first contact location P1 increases. When the torque acts on
the backrest 4 in a clockwise direction in the drawing, the bar 16
tilts to the right (and contacts the right-hand guiding segment
14). When the torque on the backrest 4 is sufficiently great, for
example more than 100 Nm, the second eccentric cam 27b and the
second locking cam 16b come into contact with each other at a
second contact location P2.
[0031] The resultant forces K2 at the four second contact locations
P2 also extend through the center point of the fitting 10, that is
to say, through the axis A, so that they generally neutralize each
other. At the second contact location P2, the second eccentric cam
27b and the associated second locking cam 16b touch each other,
that is to say, with the same pitch and a common tangent. The
normal force N2 at the second contact location P2, which is
directed radially inwards perpendicularly relative to this tangent,
is at an angle with respect to the resultant force K2 which is
referred to as a second wedge angle .beta., and at the same time
corresponds to the angle between the tangent at the second contact
location P2 and the circular arc about the axis A through the
second contact location P2. The second wedge angle .beta. is
negative, that is to say, when viewed in the figures, the regions
of the second locking cam 16b located counter to the closure
direction c protrude radially further inwards than the regions
located further in the closure direction c. Any rotation of the
eccentric 27 counter to the closure direction c is thus blocked.
The normal force N2 at the second contact location P2 therefore
acts in a closing manner, but is compensated for in a self-locking
manner by the friction, so that said resultant force K2 is
produced. As claimed in the invention, the second wedge angle
.beta. has a value smaller than 5.7.degree., preferably smaller
than 4.5.degree.. The second eccentric cam 27b and the second
locking cam 16b are material portions which are constructed in a
convex manner, at least generally in the region in which the second
contact location P2 may be located.
[0032] At the diagonally opposing bar 16, the situation is
preferably as described above. With the bars 16 which are arranged
in an adjacent manner therebetween, depending on the desired
configuration of the fitting 10, the same situation or the
situation which is mirror-inverted with respect to the closure
direction c may arise, that is to say, those bars 16 tilt in
opposing directions and the associated first eccentric cams lead in
the closure direction c.
LIST OF REFERENCE SYMBOLS
[0033] 1 Vehicle seat [0034] 3 Seat member [0035] 4 Backrest [0036]
5 Hand-operated lever [0037] 7 Transmission rod [0038] 10 Fitting
[0039] 11 First fitting member [0040] 12 Second fitting member
[0041] 13 Gripping ring [0042] 14 Guiding segment [0043] 16 Bar
[0044] 16a First locking cam [0045] 16b Second locking cam [0046]
17 Toothed ring [0047] 21 Carrier [0048] 23 Hole [0049] 24 Securing
ring [0050] 27 Eccentric [0051] 27a First eccentric cam [0052] 27b
Second eccentric cam [0053] 35 Spring arrangement [0054] 36 Control
cam [0055] 38 Projection [0056] A Axis [0057] c Closure direction
[0058] K1 Resultant force at the first contact location [0059] K2
Resultant force at the second contact location [0060] N1 Normal
force at the first contact location [0061] N2 Normal force at the
second contact location [0062] P1 First contact location [0063] P2
Second contact location [0064] .alpha. First wedge angle [0065]
.beta. Second wedge angle
* * * * *